Fluid retaining cup



Dec. 7, 1943. P. H. GRANGER FLUID RETAINING CUP 2 Sheets-Sheet 1 FiledJan. 26, 1942 2 My a M7 as v I? 4 7/ 4/ J, 7 Z J I 2 2 M 2 e M! W a Q Ew "M 2 Sheets-Sheet 2 P. H. GRANGER FLUID RETAINING CUP Filed Jan. 26,1942 Patented Dec. 7, 1943 UNITED STATES PATENT- orris 2,336,090 FLUIDRETAINING our Paul H. Granger, Los Angeles, Calif. Application January26, 1942, Serial No. 42am 4 Claims. (01. 309-33) This invention relatesto fluid retaining cups which are used as swabs and packers in casingsor the like in oil wells.

These cups usually comprise an annular body of rubber or the like whichare capable of withstanding high internal pressures while sealing withthe walls of the casing and are usually provided with some form ofreinforcing means. In order to operate satisfactorily under allconditions a cup must be sufficiently flexible to pass through thedifferent sizes of easing normally encountered, while at the same timesealingly engaging the same. Also. the cup must be sufficiently stiffand strong to withstand pressures on the order of several thousandpoundsper square inch without rupturing.

A particular object of the invention is to provide a cup which willsealingly engage with the walls of different weights of casing of thesame nominal size.

Another object of the invention is to provide an improved constructionfor sealingly fastening the cup to the mandrel.

A further object of the invention is to provide a cup with rigidreinforcing means in the walls thereof adjacent the cup follower.

Another object of the invention is to provide a cup withcircumferentially extensible reinforcing means for strengthening the cupat positions where flexibility is desired.

How these and other objects of this invention not specifically mentionedare attained will be better understood from the ensuing specificdescription of the drawings, in which:

Fig. 1 is a longitudinal section of a cup according to this inventionpositioned on a suitable mandrel in a casing;

Fig. 2 is a transverse section through the cup taken along line 22 inFig. 1;

Fig. 3 is a longitudinal section of a modified form of cup;

Fig. 4 is a transverse section thereof taken along line 4-4 in Fig. 3;and

Fig. 5 is a perspective detail of the reinforcing means employed in thecup illustrated in Figs. 3 and 4.

Referring to Figs. 1 and 2, the cup is shown as comprising an annularcup body I formed of flexible resilient material such as rubber or thelike having a flexible upper end 2 and a base portion 3. The terms upperend" and "base portion are, of course, relative since the cup mayopposite the base portion which is the portion secured to a mandrel orother mounting means such as indicated at 5.

The inner wall of the base portion 3 is recessed outward as indicated at6 to accommodate a cylindrical bushing I that makes a close sliding fitwith the mandrel 5. Bushing l is suitably secured to the cup body as byvulcanization. The upper end of the recess 6 terminates in an inwardprojecting annular ring or shoulder a of the cup body material and theinner surface of the shoulder 8 engages the mandrel.

The internal diameter of the cup body at the upper edge of the shoulder8 is greater than the internal diameter of the recess 6 and representsthe minimum diameter of the inner surface of the cup above the positionof the shoulder a. The inner diameter of the cup increases from aposition at about the center of the cup as indicated at Q and reachesthe maximum at the upper end.

The mandrel 5 is shown provided with an outward extending annular flangel i which engages the upper face ofthe shoulder 25. A removablecup-shaped cup follower is indicated at i 2 engaging the base portion ofthe cup and the lower end of the bushing I. The mandrel is threaded asindicated at l3 and is provided with a nut it which is spaced from thefollower l2 by a washer I5 and is adapted to urge the cup followeragainst the cup to hold it securely between the. flange I8 and thefollower. The shoulder 8 is squeezed between the flange II and the upperend of the bushing I and is thus forced against the mandrel 5 to form afluid-tight joint.

The annular wall of the cup body is provided with annular cavity meanscomprising an annular recess [6 extending upward from the base portionof the cup to a position intermediate the ends of the cup. The innersurface of the cup indicated at IT is subject to outward fluid pressureand the outer surface of the cup indicated at l8 faces the casing. Theannular cavity I8 is located between the inner and outer surfaces I 1.and I 8 in the wall of the cup body. whereby there is a wall portion l9located inward of the annular recess l6 which is subject to outwardfluid pressure.

A rigid annular reinforcing member 2| in the form of acontinuous metalcylinder is shown located within the cavity I 6 adjacent the lower endthereof and the base portion of the cup. The reinforcing member 2| maybe secured to the cup body as by vulcanizing or it may be free to movein the cavity. The lower end of the cavity is shown closed with a thinannular rubber member 22 vulcanized in place. The member 2| extendsupward from a position below the upper end 23 of the cup follower 2 to aposition above said upper end and intermediate the ends of the cup andis in position to engage the outer surface of the wall portion l9 andresist radial outward loads transmitted from the inner surface ll of thecup. Themember 2| is separate and spaced radially outward from thebushing 1.

Preferably further reinforcing means is provided in the wall I above theupper end of the rigid reinforcing member 2| as in the portion ofannular cavity l6 above the member 2| Such additional reinforcing meanspreferably should reinforce the cup against outward fluid pressure fromwithin without appreciably decreasing the cups flexibility, since theposition of such reinforcing means is in the portion of the cup whichshould be flexible. For this purpose I may provide one or' more splitrings such as indicated at 24 of steel or other flexible resilientmaterial of high tensile strength.

The rings 24 are circumferentially extensible and are preferably of suchdiameter as to not engage the inner walls of the cavity l6 when the cupis in its rest position as indicated and they are free to move withrespect to the side walls of the cavity during circumferentialextension. The inner diameter of the rings 24 is preferably such thatthe inner surfaces thereof will be engaged by the wall portion l9 afterit has been deformed outward by outward fluid pressure whereby the ringswill assist the wall portion in resisting radial outward loads.

The uppermost ring is indicated in plan at 24a in Fig. 2 and a portionof the next lower ring is indicated in plan at 2417. The rings arepreferlocated the base portions 35 of a plurality of arcuatelongitudinally extending overlapping leaves 38 of steel or otherrelatively stiff reinforcing material.

Portions of two overlapping leaves are shown in perspective in Fig. 5and are designated 36a and 36b. In order to hold the leaves in positionin overlapping relation the base portions thereof are folded or bentupward about 180 angle as indicated at 36c and 36d. The direction ofbending is opposite in successive leaves as will be noted particularlyfrom an inspection of Figs. 4 and 5. The radial width of the baseportions is such as to provide a loose fit thereof in the annular recess36. The base portions 360 and 36ddo not extend for the completecircumferential extent of the leaves whereby the end portions 36c and36f of the leaves 36e-and 361) respectively may overlap withoutinterference from the bentover base portions. Circumferential movementof the leaves relative to one another is prevented ably provided withcircumferentially spaced butt ends. The butt ends of the rings 24a and24!) are shown at 24c and 24d, respectively. The butt ends of theremaining rings are shown at 24c, 24) and 24g. It will be notedthatpositions of the splits or butt ends of each ring are circumferentiallyspaced from an adjacent ring.

It will be noted that the upper end 2 of the cup body is provided with aflexible annular outward projection 26 which is adapted to engage theinner wall of the casing 4. This projection allows the cup toaccommodate itself to different sizes of casing which are smaller thanthe sizes of easing shown. Upon entering a smaller casing the flexibleupper portion of the cup body yields at the position indicated at 21where the wall thickness abruptly decreases from that obtaining at theposition of the projection 26. At the same time the projection 26maintains sealing engagement with the wall of the casing. With theillustrated embodiment of the invention the minimum wall thickness ofthe cup body I occurs at the lower end of the projection 26, .at theposition indicated at 21. Thus the cup is readily deformable at thatposition.

Referring to Fig. 3 a cup is indicated at 30 which is identical to thecup illustrated in Fig. 1, with the-exception that the shape of theannular cavity and the construction of the reinforcing means containedtherein is different. The annular cavity is indicated at 3| and it willbe noted that the base portion 32 thereof is of greater radial extentthan the upper portion 32a. The base portion 32 contains a solidcylindrical reinforcing member 33 of substantially the same height asthe member 2| of Fig. 1 and located insubstantially the same position inthe annular cavity 3|. The upper face of the member 33 is provided withan annular recess 34 in which is or limited through abutment of the endsof said leaves with the ends of the bent-over base portions 36c and 36d.v

Inner surface 31 of the wall 38 of the cup is subject to radiallyoutward fluid pressure and the annular recess 3| is located in the wall38 outward of the surface 31 and has a wall portion 39 subject to radialoutward force. The reinforcing means 33 and 36 are located in theannular cavity 3| and are adapted to engage the outer surface of saidwall portion 39 to resist its outward movement from radial outwardforces on the surface 31.

In the preferred embodiment the ring 33 is preferably a solid annularmember as distinguished from a split ring, and the reinforcing meanscomprising the overlapping leaves 36 is preferably capable ofcircumferential extension upon expansion of the cup. Suchcircumferential extension is obtained by movement of the overlappingportions 36e and 36f over one another. Obviously, the overlap of theleaves should be sufflcient so that the leaves will remain inoverlapping relation for all normal operating conditions of the cup.

Although I prefer a construction in which the circumferentiallyextensible reinforcing means is loose in the annular cavity and spacedtherefrom as shown so that an initial expansion of the cup may beobtained before the reinforcing means is efiective, I may as analternative mold the circumferentially extensible reinforcing means andthe inextensible reinforcing means in place when the cup is molded. Theresulting cup will not be quite as flexible as the preferred cup butwill still retain some of its advantages in view of the circumferentialextensibility of the upper reinforcing means.

It will be noted that in the illustrated forms of the invention therigid reinforcing member such as the member 2| of Fig. 1 extends from aposition above to a position below the upper end of the bushing 1 andintermediate its ends, is separate therefrom and spaced from the bushingby a portion of the flexible cup Wall material. It should also be notedthat the rigid reinforcing means and the circumferentially extensiblereinforcing means need not be directly above one another. In other,words, the portion of the cavity means containing the'circumferentiallyextensible reinforcing means located at a position above the rigidreinforcing means need not be directly above the portion of the cavitymeans containing the rigid reinforcing means.

I claim:

1. A fluid retaining cup for use in a casing or the like, comprising aflexible cup body having an annular wall whose inner surface is subjectto outward fluid pressure and whose outer surface faces the casing orthe like, said wall having an annular cavity and having a wall portiondisposed inward of said cavity, a rigid annular reiniorcing memberextending upward in the cavity from adjacent the base of the cup, andone or more circumferentially extensible resilient split ringreinforcing members located in the cavity above the annular reinforcingmember, and being free to move with respect to the side walls of thecavity during circumferential extension, the reinforcing members beingadapted to engage said wall portion to resist radial outward loads.

2. A fluid retaining cup for use in a casing or the like, comprising acup body having a flexible annular wall whose inner surface is subjectto outward fluid pressure, said wall having an annular cavity and havinga wall portion disposed inward of said cavity, the inner wall of the cupbody adjacent the base of the cup being recessed outward to provide abushing-receiving recess; a cylindrical bushing in saidbushing-receiving recess extending upward from the base of the cup; arigid annular reinforcing member extending upward in the cavity from aposition intermediate the ends of the bushing to a position above theupper end of the bushing, said reinforcing member being spaced outwardof the bushing and adapted to engage said wall portion to resist radialoutward loads; and circumferentially extensible reinforcing meanslocated-in said cavity above said rigid reinforcing member and beingfree to move with respect to the side walls of the cavity duringcircumferential extension.

3. A fluid retaining cup for use in a casing or the like, comprising acup body having a flexible annular wall whose inner surface is subjectto outward fluid pressure, said wallhaving an annular cavity locatedoutward of said inner surface and extending upward from the base of thecup to a position intermediate the ends of the cup; a rigid annularreinforcing member in the lower portion of said cavity adapted to resistradial outward loads transmitted from said inner surface; andcircumferentially extensible reinforcing means comprising a plurality ofsplit rings located in said cavity above said rigid reinforlcng memberand being free to move with respect to the sidewalls of the cavityduring circumferential extension.

4. A fluid retaining cup foruse in a casing or the like, comprising acup body having a flexible 'annular wall whose inner surface is subjectto outward fluid pressure, said wall having an annular cavity locatedoutward of said inner surface and'extending upward from the base of thecup to a position intermediate the ends of the cup; a rigid annularreinforcing member in the lower portion of said cavity adapted to resistradial outward loads transmitted from said inner surface; andcircumferentially extensible reinforcing meaps comprising a plurality oflongitudinally extending overlapping leaves located in said cavity abovesaid rigid reinforcing member and being free to move with respect to theside walls of the cavity during circumferential extension.

PAUL H. GRANGER.-

